Advanced External Intercostal Muscles Quiz

Q1. What is the posterior extent of an external intercostal muscle?

• Sternal angle
• Costal margin only
• Spinous processes
• Rib tubercles

Q2. Which structure continues an external intercostal from the costochondral junction toward the sternum?

• External intercostal membrane
• Fibrous pericardium
• Internal intercostal membrane
• Transversalis fascia

Q3. Which description best characterizes external intercostal fiber orientation?

• Downward and forward
• Directly vertical
• Directly medial
• Downward and backward

Q4. Why does contraction of external intercostals favor inspiration?

• They elevate ribs and expand the thorax
• They elevate the diaphragm
• They close the pleural cavities
• They compress the lungs directly

Q5. Which rib attachment is pulled upward during effective external intercostal contraction?

• The sternum only
• The vertebral body only
• The rib above only
• The rib below

Q6. Which action of the external intercostals supports the pump handle and bucket handle movements?

• Depression of the ribs
• Elevation of the ribs
• Rotation of the vertebrae
• Retraction of the scapulae

Q7. Which layer separates the external intercostals from the innermost intercostals?

• Parietal pleura
• Visceral pleura
• Internal intercostal layer
• Endothoracic fascia

Q8. Which relationship explains why external and internal intercostal fibers are easily distinguished?

• External intercostals lie inside the pleural cavity
• Only internal intercostals are skeletal muscle
• Only external intercostals attach to ribs
• Their fiber directions differ

Q9. What functional effect does external intercostal tone have on the thoracic wall?

• It controls the aortic valve
• It stabilizes the intercostal spaces
• It closes the main bronchi
• It contracts the visceral pleura

Q10. Which description best summarizes the external intercostal muscles?

• Superficial rib elevators that assist inspiration
• Mediastinal muscles controlling the bronchi
• Deep rib depressors confined to the sternum
• Pleural muscles controlling lung recoil